Concern is growing for the well-being of four journalists , three of them American citizens , apparently detained in Iran this week , according to The Washington Post .

The newspaper reported Thursday that its Tehran correspondent Jason Rezaian , a U.S. citizen , and his wife , Yeganeh Salehi , appeared to have been detained Tuesday evening .

Two freelance photojournalists , both American citizens , also have been detained , according to The Post . The paper said officials had not yet named the pair .

An Iranian official confirmed to CNN that Rezaian and Salehi are among three journalists being held by authorities . He did not say what they have been charged with .

The third journalist is a freelance photographer , the official said on condition of anonymity .

It 's not clear why there is a discrepancy in the number of journalists held .

Gholam-Hossein Esmaili , the director general of the Tehran Province Justice Department , is quoted by Iran 's official IRNA news agency as saying a `` Washington Post journalist has been detained for some questions and after technical investigations , the judiciary will provide details on the issue . ''

He did not specify on what grounds the correspondent , whom he did not name , was being held .

Iranian security forces are vigilant about all kinds of enemy activities , Esmaili added , according to IRNA .

In a statement Thursday , Washington Post foreign editor Douglas Jehl said `` we are deeply troubled by this news and are concerned for the welfare of Jason , Yeganeh and two others said to have been detained with them . ''

He described Rezaian as `` an experienced , knowledgeable reporter who deserves protection and whose work merits respect . ''

` Dismal record '

The Committee to Protect Journalists said it was alarmed by The Post 's report and urged Iran to release the four journalists .

`` We call on Iranian authorities to immediately explain why Jason Rezaian , Yeganeh Salehi , and two other journalists have been detained , and we call for their immediate release , '' said Sherif Mansour , its Middle East and North Africa program coordinator .

`` Iran has a dismal record with regard to its treatment of imprisoned journalists . We hold the Iranian government responsible for the safety of these four . ''

The Iranian mission to the United Nations in New York is following up on the case , spokesman Hamid Babaei said .

`` We will inform the media as soon as we receive any news from Tehran , '' Babaei said .

According to The Washington Post , Rezaian , 38 , holds American and Iranian citizenship . He has been the paper 's Tehran correspondent since 2012 .

His wife , an Iranian citizen who has applied for U.S. permanent residency , is a correspondent for the UAE-based newspaper the National , The Post said .

Members of Rezaian 's family said they did not want to comment at this time , the paper added .

Thomas Erdbrink , Tehran bureau chief for The New York Times , said via Twitter , `` I strongly condemn the arrest of my friend and colleague @jrezaian and his wife @YeganehSalehi , and two photographers , also friends . ''

Past detentions

Rallies are being held in Iran to mark Quds -LRB- Jerusalem -RRB- Day on what is the last Friday of the holy month of Ramadan .

Muslims worldwide mark this day each year to remember the plight of the Palestinians . Several foreign journalists are in Tehran to cover the event , which includes an anti-Israel demonstration after the Friday prayers .

According to CPJ research , there are 35 journalists in prison in Iran .

The organization also highlights past instances in which Iran has detained international journalists , including the case of U.S. freelancer Roxana Saberi .

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Iranian official says Jason Rezaian and Yeganeh Salehi are among three journalists held

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The Washington Post says four journalists have apparently been detained this week

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They include Jason Rezaian , a U.S. citizen , and his wife , journalist Yeganeh Salehi

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The others are two freelance photojournalists , the Post says